[Python-Dev] generators and with (original) (raw)

dustin at v.igoro.us dustin at v.igoro.us
Sun May 13 17:33:45 CEST 2007

On Sun, May 13, 2007 at 04:56:15PM +0200, tomer filiba wrote:

why not add enter and exit to generator objects? it's really a trivial addition: enter returns self, exit calls close(). it would be used to ensure close() is called when the generator is disposed, instead of doing that manually. typical usage would be: with mygenerator() as g: g.next() bar = g.send("foo") -tomer

A better example may help to make your case. Would this do?

with mygeneratorfn() as g:
    x = get_datum()
    while g.send(x):
        x = get_next(x)

The idea then is that you can't just use a 'for' loop (which will call close() itself, IIRC) because you want access to the generator itself, not just the return values from g.next().

I wouldn't have a problem with this proposal, but I consider the snippet above to be fairly obscure Python already; the requirement to call g.close() is not a great burden on someone capable of using g.send() et al.

Dustin

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